program ttext;
type cuv = set of char;
var c,l:cuv;
i:char;
nr: longint;
f,g: text;
begin
assign(f,'D:\Programming\Programs\Probleme\text.in');
assign(g,'D:\Programming\Programs\Probleme\text.out');
reset(f);rewrite(g);
for i:='A' to 'Z' do begin
 c:= c + [i];
end;
for i:='a' to 'z' do begin
 c:= c + [i];
end;
while not eoln do begin
 read(f,i);
 if i in c then
  nr:=nr+1;
end;
write(g,nr);
close(f);close(g);
end.